[Mingw-users] Qt-DLL size - gcc compared to msvc

[Heiko G. <hg...@te...>]

Hi,

when I build the Qt3*-DLL with the current mingw distribution including
gcc3.2 the result is quit a large DLL. Large at least compared to what one
gets using the Microsoft compiler vc++ 6.o. It's a factor of 2.5 (5 MByte).
This difference is so big that I assume a mistake involved. Maybe someone on
this list can bring some light into the issue.

In the following the --export-all-symbols is needed because gcc seems to
handle the dllexport/import mechanism incorrect, especially when inlining is
involved. Anyway the influence on the size is not dramatic.

Here are the dll sizes from different builds:

0. Using MSVC 6:
     QT.DLL = 3.51 MB
1. gcc: no special compile/link options:
     Qt.dll = 12.38 MB
2. --export-all-symbols:
     Qt.dll = 12.81 MB
3. --export-all-symbols, -O1, -s
     Qt.dll = 9.07 MB
4. --export-all-symbols, -O3, -s
     Qt.dll = 9.82 MB
5. --export-all-symbols, -Os, -s
     Qt.dll = 8.78 MB
6. --export-all-symbols, -Os, -s and using stdc++ as a DLL.
     Qt.dll = 8.66 MB

By the way: The mingw-gcc compiled QT-DLL works fine. There is no (obvious)
performance difference to the one compiled with msvc, just the weird size
difference.

Greetings
Heiko